Relationship Between Posterior Shoulder Tightness and Lower-Limb Flexibility in College Baseball Players.

Context: Posterior shoulder tightness evaluated as limited glenohumeral internal rotation and horizontal adduction is a risk factor for throwing-related shoulder and elbow injuries. Given that the throwing motion uses the entire body kinematics, limited lower-limb flexibility might be associated with posterior shoulder tightness. Therefore, we aimed to investigate the relationships between posterior shoulder tightness and lower-limb flexibility in college baseball players.

Supraspinatus tendon thickness and subacromial impingement characteristics in younger and older adults.

Background: Subacromial impingement (SAI) may be a cause of age-related rotator cuff abnormalities; therefore, the purpose of this study was to compare SAI characteristics between younger and older adults. In addition to the fact that thickened supraspinatus tendon (SST) indicates tendon abnormalities, SAI characteristics have been recognized as follows: greater SST thickness, reduced acromiohumeral distance (AHD), greater reduction of AHD (∆AHD) with arm elevation, and a higher percentage of SST within AHD (i.e.

Supraspinatus Tendon Changes and Glenohumeral Range of Motion in College Baseball Players.

Baseball players commonly show altered glenohumeral range of motion during internal rotation, external rotation, total rotation, and horizontal adduction. These altered ranges of motion appear to be associated with throwing shoulder injuries, which frequently involve the supraspinatus tendons; thus, we aimed to examine the relationship between altered glenohumeral range of motion and supraspinatus tendon changes in collegiate baseball players. To investigate this association using the Pearson correlation coefficient, we measured glenohumeral internal rotation, external rotation, total rotation, and horizontal adduction ranges of motion and supraspinatus tendon thickness in 22 college baseball players.

Comparing trapezius muscle activity in the different planes of shoulder elevation.

[Purpose] The purpose of this study was to compare the upper, middle, and lower trapezius muscles' activity in the different planes of shoulder elevation. [Subjects] Twenty male subjects volunteered for this study. [Methods] Surface electromyographic (EMG) activity for each of the three regions of the trapezius muscles in the three different planes of elevation were collected while the participants maintained 30, 60, and 90 degrees of elevation in each plane.

Does restriction of glenohumeral horizontal adduction reflect posterior capsule thickening of the throwing shoulder?

[Purpose] Glenohumeral posterior capsule tightness possibly relates to posterior capsule thickness (PCT). The purpose of the current study was to analyze the relationships between PCT and glenohumeral range of motion (ROM) in horizontal adduction (HAdd) and internal rotation (IR). [Subjects and Methods] This study recruited 39 healthy collegiate baseball players.

Rehabilitation Exercises to Induce Balanced Scapular Muscle Activity in an Anti-gravity Posture.

[Purpose] The purpose of this study was to compare the intramuscular balance ratios of the upper trapezius muscle (UT) and the lower trapezius muscle (LT), and the intermuscular balance ratios of the UT and the serratus anterior muscle (SA) among prone extension (ProExt), prone horizontal abduction with external rotation (ProHAbd), forward flexion in the side-lying position (SideFlex), side-lying external rotation (SideEr), shoulder flexion with glenohumeral horizontal abduction load (FlexBand), and shoulder flexion with glenohumeral horizontal adduction load (FlexBall) in the standing posture. [Methods] The electromyographic (EMG) activities of the UT, LT and SA were measured during the tasks. The percentage of maximum voluntary isometric contraction (%MVIC) was calculated for each muscle, and the UT/LT ratios and the UT/SA ratios were compared among the tasks.